‘‘The weather got cold, so I haven’t been training much,’’ she murmured. ‘‘Then suddenly today I had to do this run . . . and I just . . . couldn’t do it.’’

Clad in a purple wool sweater to fend off the winter morning chill, the 18-year-old student collapsed in the arms of her friends after the run at Beijing’s prestigious Tsinghua University. They held up each of her elbows as they escorted her from the track.

Such scenes are increasingly common on the tracks and fields of China, which, despite its formidable performance in recent Olympic Games, has seen the fitness of its young people decline.

‘‘Our economic power has grown while our people’s physiques have not only failed to improve, but have deteriorated. That’s unacceptable,’’ said Sun Yunxiao, deputy director of China Youth and Children Research Center in Beijing. ‘‘This is something that worries the nation.’’

The government has urged schools, especially elementary and secondary schools, to beef up their physical education after an outcry touched off by events late last year.

Two Chinese college students collapsed and died when they were testing for an annual mandatory 1,000-meter run in late November. Another two runners in their early 20s died in 5,000-meter and 10,000-meter races during a sporting event in Guangzhou. The sudden deaths were considered accidental, but the spate of them was enough to draw attention to physical education in China.

Several universities canceled their men’s 5,000-meter and women’s 3,000-meter events from their fall sports meets, for reasons including fear of liability and lack of interest.

The dismal state of fitness in the younger generation prompted a well-known and hawkish military officer, Major General Luo Yuan, to bemoan the prospects for China’s future in a recent editorial in the state-run Global Times newspaper.

‘‘Femininity is on the rise, and masculinity is on the decline,’’ Yuan thundered. ‘‘With such a lack of character and determination and such physical weakness, how can they shoulder the heavy responsibility?’’

Sun attributes the decline to an obsession with academic testing scores in China’s high competitive environment for college admissions, as well as a proliferation of indoor entertainment options such as video games and surfing the Internet.

Sun said an overwhelming majority of Chinese young students cited their academic performance as their parents’ top priority, with some saying it was the only thing that mattered to parents.